This invention relates to cursor control, as well as panning and scrolling in displays of hand-held devices.
In many of today""s electronic computing devices, such as personal computers (PCs), portable digital assistants (PDAs), electronic games, and even cell phones include a screen display. Users communicate with the devices by receiving information via the display, and providing information through one or more input devices, which is reflected in the display. The most common input devices, as least in connection with PCs, are the keyboard and a pointing device such as a track-ball, a mouse or a joystick. Simply described, a mouse consists of a ball and case. In use, the casing is held by the operator to place the ball against a given dedicated surface, and movement of the case causes the ball to roll on the surface in any desired two-dimensional direction. The movement of the ball is encoded and communicated to the computer, which translates the ball""s movement to a movement of a displayed cursor icon on the PC""s screen. The mouse also includes one or more buttons that, when pushed, initiate some other action by the PC that, typically, is related to the position of the cursor when the button is pushed. The kinds of actions that are triggered includes manipulations of the displayed image through scrolling or panning.
The main drawback to the mouse device, particularly for portable devices such as PDAs and cell phones, is that it requires a dedicated, relatively flat and unobstructed area for moving the mouse around. With respect to small, portable, devices such as PDAs and cell phones, that is a major drawback. What these devices employ, therefore, is touch sensitive screens in combination with a stylus (for example, the Palm Pilot), or push buttons (for example, most cell phones). Other devices have also been proposed, such as a thumbwheel (in U.S. Pat. No. 5,590,382) and a moveable multi-position switch (in U.S. Pat. No. 4,739,128). These input devices represent an advance in the art, but when a person desired to use one handed operation, these input devices are somewhat awkward to work because the person needs to hold the electronic computing device, to operate the input device to achieve cursor control, and to push activation buttons; all with a single hand.
An advance in the art is realized by providing for movement of a screen cursor in response to the spatial orientation of hand-held electronic computing devices. This is achieved with a force-sensing mechanism that is built into the electronic computing device which, by sensing the gravitational pull, assists in determining the spatial orientation of the computing device by sensing the net force that is applied thereto, and assists in determining the position of cursor 120. In one illustrative embodiment the force-sensing mechanism comprises a pair of accelerometers that provide a signal corresponding to the gravitational force applied to the accelerometers. A processor responsive to the signals of the accelerometer converts those signals to cursor position signals.